Grease strainer



July l23 1946.`

E. W. DAVIS GREASE STRAINER Patented uy 23, 1946 GREASE STRAINERx n A n x Ernest vW. Davis, River Forest, Ill., assignor to Stewart-Warner Corporation, corporation ofvVirginia l.

Chicago, Ill., a

Application `Maren 31, 1943, serial N9. 481,221

My invention relates to strainer and more particularly to strainers for separating particles yof foreign matter from grease discharged into a high pressure grease line, leading to a plurality of metering devices in a centralized` lubricating system adapted to proportion the ow of grease to a, plurality of bearings. The prior art discloses many such centralized lubricating systems, vfor which the strainer of this invention is well adapted.

The necessity for such a, strainer is obvious when it is considered that practically all commercial lubricating .greases co'ntain particles of lint, scale, grit, libres, and other extraneous substances, the adverse inuence of which may prevent continued successful operation vof the aforesaid metering devices. Unlike oil, grease does not permit such impurities Vto settle by the action `of gravity, and as the methods of handling grease are generally less conducive to cleanlinessl than the methods ordinarily used in dispensing oil, the necessity of installing a strainer in a grease line is quite obvious.

The strainers heretofore used for this purpose vcomprise a hollow body member containing a, wire screen., The body member is often suppliedwith a removable. plug to facilitate convenient removal of the screen when cleaning is necessary. Such strainers are quite satisfactory if they are cleaned before they become clogged with impurities, but

in actual practice they are usually neglected..

Then when the screen becomes cloggedwith irnpurities, thevhigh grease pressure, which may be thousands of pounds per square inch, bursts the screen and .allows the accumulated mass of impurities to travel along with the owing grease to the metering devices, which' then become inoperative. v v Y The principal object of this invention is to pre- .vent this objectionabley bursting of the screen. This object is accomplished by incorporating a valve in the body of the strainer, which Valve is in series with the screen, and by providing means, operative upon partial clogging of the strainer, for closing the valve.

Referring to the drawing:

Figure 1 is an end elevation of the strainer of this invention;

Figure 2 is a sectional side elevation of the same, the section being taken on the line 2, 2, in Figure 1; and

Figure 3 is a similar section of a modied form of the strainer shown in Figure 2.

The body member 4 is preferably constructed of air furnace iron, and is provided with an inlet f 4c1aims. (o1. 21o- 166) E, and an outlet 8, with a grease passageway I0, extending from the `inlet 6, to the outlet 8. The cylindrical portion I2 is bored at each end to receive a loosely fitting screening element I4, `having end pieces I6 and I8, held in position by the connecting rod 2l) which serves to hold the cylin-V drical screening member from collapsing longitudinally. The openings 22, 22 in th'e end piece I6;v permit the passage of greaseV to the interior of the screening element I4. Y

The passageway I Il includes a port disposed between the inlet and the outlet and controlled by a sphericalcheck'valve 24. The spherical valve 24 is normally held off the valve seat 26 by the end thrust of the connecting rod 20, which is urged in Va direction towards the valve 24 by means ofv the compression spring 28. The

' screening element I4,.and spring 28 are assemwbled in` the body memberllA through the threaded opening 30, which isA then closed by the removable closureplug 32. The valve 24 is assembled in the body member 4 through the threaded opening 34A which is then sealed by the removable closure plug.36. l

The operation of this strainer is as follows:

Grrease owing through the inlet 6 passes around the valve 24,*through the openings 22, 22, into the screening element I4, through the interstices of the screening element I4 and out through the outlet 8. Particles of foreign substances in the grease are separated from the grease as it passes through the screening element I4, so that grease discharged through the outlet 8 is relatively clean.

After longA continued service the screening element I4 may become clogged with the aforesaid particles', whereupon the differential grease'pressure across the screening element I4 causes the .entire screening element I4 to move downwardly and towards'the right, thereby compressing the spring 28, and thereby permitting the valve 24 to close against the valve seat 26, so as to prevent further passage of grease through the screening element I4. Since greaseis a relatively viscous fluid it will tend to carry the valve 24 toward its seatV 26 even though the strainer body be inverted with respect to the position in which it is shown in Figs. l and 2.

The -degree of clogging of the screening element I4 which will cause the valve 24 to close, will, of course, depend upon a number of factors, but, in ultimate analysis, the valve 24 will close when the differential pressure on the opposite sides of the end piece I8 is sufficient to compress the spring 28 to the extent necessary to remove the ablyreduced due to the increased resistance toV It will be noted grease flow through the strainer. that the portion of vthe bore through the cylinfdrical portion l2 is in free Vcommunication with Vthe outlet opening 8 through a hole 31.

When this strainer is usedv in a hand operated greasing system, the inability of thev operator to force grease through the systemnoties himthat the strainer is clogged and needs cleaning.

In the embodiment illustrated in Figure 3,-av

semi-spherical valve 38 yis screwed on the connectingv rod '23. The operation of this strainer is the'same as that kof the strainer illustrated in Figure 2,'except that the valve 38 is closed by the movementfoi` the grease. Y

Without. further elaboration, the foregoing will so fully explain my invention that others may, by

applying knowledge current at the time of application, readily adapt the same for use under various conditions of service.

I claim:

l. In a strainer device, the combination of a body member having inlet and outlet openings with a passage .connecting them for flow of 'fluid from said outlet to said inlet, said passage in- 1.,

Y the valve open until the screen becomes so clogged that the pressure of fluid entering at the inlet is sufficient to Ymove the screening element away from the port in opposition to said spring means.

V2. Ina strainer device, the combination of a body member having a flow passage for uid extending through it, with inlet and outlet openings respectively at opposite ends of said passage' and in substantially axial alignment, a screening element having a pervious cylindricall wall and disposed with its axis at an angleY tothe common axis of said inlet and outletfone end of said screening element being open to' receive fluid from the inlet-end Vof the passage and said fluid being` discharged through said pervious wall of the screening element into the passage and toward its outlet, guide means in said body member in which the screening element isfmounted for limited movement in the direction of its axis, a check valve in the passage and a seat therefor element, said valve ybeing adapted't control the 4 now ofA fluid from the inlet toward said screening element and seating in the direction of said ow, an end wall on the other end of said screening element, means extending rigidly from said screening element into engagement with said valve and serving to hold the valve open at one limit of movement of said screening element, and spring means urging Asaid element tward. said iiinit. n

3. In a strainer device, the combination of a body member havinginlet and outlet openings adapted for connection with conduit means, said connecting rod 20instead of being closed by Y disposed adjacent the lopen -end of the screening 5615 body member havingua bore extending at an angle to YVthe axis of Ysaid outlet withV one side of said fbbre open vto said outlet andwith a port atene` vend of the bore opening to the inlet, a screening ,element Vhaving apervious cylindrical wall disposed in said bore, the bore providing guide means for 4limited movement of the screening element in the direction of its axis, one end of said screening element'bein'g open to receive Vfluid from the inlet through said port,sa'i`d fluidl being.' :dis-V charged to the outlet through said pervious wall of the screening element, a valve seat at said port and a valve cooperating therewith to control the ow of fluid vfrom said inlet toward said outlet, said valve seating in the direction of ow toward the open endbf the screening element, an end wall on the otherend of said screening element, means extending rigidly from said end wall into engagement with said valve and serving to hold the valve open at one limit of movementy of said screening element, spring means-urging said element toward said limit, and a plug closing one end of said boreand removable to permit removal of the screening element. Y y

4. Ina strainerrdevice, the combination of a body member having threaded inlet and outlet openings in' v'substantiallyV ax-ialY alignment and having a boreextendin'g at an angle to the common axis of said inlet and outlet, said bore having one side open to the outlet and having a port' at one end opening to the inlet, a screening element including a pervious cylindrical wall disposed in said bore and guided for limitedl movement thereininthe direction VofV its axis, a valve seat at said port andy a valve cooperating therewith to control now of'iiuid from said inlet toward said outlet, said valve seating in thevd-irection of flow,-the end 'of said'screening element `toward the port being open to receive fluid from the -inlet'and said liuid being discharged through said pervious Wall of the screening element to the outlet, means extending rigidly from said screening element into engagement` with the valve andfserving'to hold thevalve openrat one limit of movement of said screening element, a threadedplug closing one end ofthe bore, a spring reacting between said plug and the screening element urging said element toward said limit of its movement and normally holding the valve open, the removable threaded plug being dimensioned to permit removal of the spring and rscreening elementfrom thebore. ERNEST W.A DAVIS. 

